162 General Notes. 
The character of the vertebrate fauna is indicated by the follow- 
ing table: 
Be Se re reer cca 12 BUDOLUGEIE i's ors cere so secceues 52 
Crocodilitiws wise Ci cides 3 SOOMIOGGONRs oobi oe sce veel 3 
Testudinata ................. 5 CPODGOIND sss 05 ecan an 49 
Rhynchocephalia............ 3 DRROODOGM. 5 6 vic sae oa eaen 28 
CPO oso ed ease ceieee cs 7s 8 1 Quadrumana...... ........ 4 
NOT isk ieee Peas Condylarthra. i.. ccris 24 
Mammalia. ocassion s n 93 ly Pode. ei na 
Marsupialia. a eceso oaint ona 
TOME 6 seee o a 106 
In 1874, the writer advanced the proposition that the ancestors 
of modern placental mammalia would be found to be “ plantigrade 
pentadactyle bunodonts.” This anticipation was partly realised in the 
fauna of the Wasatch epoch subsequently discovered, but is complete- 
ly so, in the characters of the mammalia of the Puerco epoch. 
the placentals, and probably the Implacentals also, were “ plantigrade 
pentodactyle bunodonts.” More than this, the placentals nearly all 
present the primitive type of dendition of the maxillary series, 
since the superior no less are nearly all of the tritubercular type. 
But four species out of the eighty-seven placentals are quadrituber- 
cular. In the inferior molars the tuberculosectorial, or quinque- 
tubercular type of dertition is extensively prevalent, but not so gen- 
erally so as the superior tritubercular. Thus of the eighty-seven 
placentals sixty-four present the primitive type. 
n its relations to other faunæ, the Puerco is totally distinct as 
to species. No species comes to it from an earlier epoch, and none 
continued unchanged after it. Of genera not widely distributed in 
time, one of lizard-like Rhynchocephalia, Champsosaurus, comes 
over from the Laramie, with a genus of tortoises Compsemys. 
Another genus of tortoises, Dermatemys, probably commences at 
this epoch, to continue through the Wasatch and Bridger Eocenes 
to the present time, since it still exists in Mexico. Among Mam- 
malia, one genus only continues later, since Didymictis is found in 
the Wasatch and Wind-river formations. None other continues 
after the close of the Puerco. Not only this, but the entire family 
of the Periptychide ceased at that period. The same is true of 
the Amblypod family Pantolambdide. One of the most im- 
portant features of the fauna is, however, the presence of eleven 
species of the Marsuspialia Multituberculata, a suborder which com- 
menced in the Triassic age, and which terminated its existence so 
far as the Northern Hemisphere is concerned, with the end. of the 
Puerco epoch. This series of animals gives a Mesozoic character 
to the fauna, which is not necessarily counterbalanced by the 
characters of the remaining types. The placentals are in all 
probability those which existed during the latter part of Mesozoic 
time, and the absence of some of the forms of the Eocene increases 
the weight of the impression thus produced. Thus two orders 
